F=ma (Cart) LAB: directions

Proving F=ma

Remember:  You will keep the pulling force the same for ALL trials.  

You will vary the mass of the cart – use 5 different masses.  

You will run 5 trials for each mass.

• Go to the blog and download the spreadsheet template for the F=ma post.
• Save a copy of this ‘velocity template’ file into the folder that corresponds to your period number.
• Set the sampling rate on the motion detector to 25 samples per second.
• Be sure there is at least 20cm between the motion detector and the cart.
• Be sure that the motion detector can ‘detect’ the cart for the entire duration of the trial.
• After you have run what you think is a successful trial, copy and paste 10 position and time data points from Logger Pro into the excel velocity template.  You should paste over the existing data.
• The slope of the velocity-time graph is the acceleration for that trial.  Put this value in the data table you were provided by the instructor.
• Be sure to fill in the value for the pulling force you are using.
• Be sure to fill in the value for the mass that is being used for the 5 trials.
• Calculate the uncertainty for the acceleration by taking the difference between the max and min value and dividing by two.
• Prepare a summary data table with the following columns:  m (show uncertainty), 1/m (show uncertainty), a (show uncertainty).
• Make a graph of a vs. 1/m.  The slope of this line should equal your pulling force.  You can make your graph with excel or use the graph paper provided

F=ma Processing sheet

F=ma Data Sheet